Ability of Cystatin C to Detect Changes in Glomerular Filtration Rate After ACE Inhibition in Patients with Uncomplicated Type 1 Diabetes

In the early 1980s, studies in type 1 diabetes suggested that glomerular filtration rate (GFR) loss begins with the onset of macroalbuminuria. However, recent evidence indicates that up to one-quarter of subjects with diabetes reach a GFR of less than 60 ml/min/1.73 m2(chronic kidney disease [CKD] stage 3) before developing micro- or macroalbuminuria. Furthermore, the prospective loss of GFR can be detected in early diabetic nephropathy (DN) well before CKD stage 3. Early GFR loss usually reflects DN in type 1 diabetes but, in older patients with type 2 diabetes, the assessment of early GFR loss needs to take into account the effects of aging. The assessment of GFR is now feasible at clinical level, using formulas based on serum creatinine, age, gender, and ethnicity. Overall, the estimation of early GFR loss is more accurate with the Chronic Kidney Disease Epidemiology (CKD–EPI) formula than with the Modification of Diet in Renal Disease (MDRD) study formula, but there is some evidence that the CKD-EPI formula does not exhibit better performance than the MDRD formula for estimating GFR in diabetes. Both formulas underestimate GFR in the hyperfiltration range. Formulas based on the reciprocal of cystatin C can also be used to estimate GFR, but their cost and lack of assay standardization have delayed their use at clinical level. In summary, early GFR loss is an important marker of DN as well as a potentially reversible target for interventions in DN.

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Comparison of Glomerular Filtration Rate Estimation from Serum Creatinine and Cystatin C in HNF1A-MODY and Other Types of Diabetes

Journal of Diabetes Research ◽

10.1155/2015/183094 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Magdalena Szopa ◽

Maria Kapusta ◽

Bartlomiej Matejko ◽

Tomasz Klupa ◽

Teresa Koblik ◽

...

Keyword(s):

Type 2 Diabetes ◽

Glomerular Filtration Rate ◽

Serum Creatinine ◽

Glomerular Filtration ◽

Cystatin C ◽

Filtration Rate ◽

Glomerular Filtration Rate Estimation ◽

Measured Gfr

Introduction. We previously showed that in HNF1A-MODY the cystatin C-based glomerular filtration rate (GFR) estimate is higher than the creatinine-based estimate. Currently, we aimed to replicate this finding and verify its clinical significance. Methods. The study included 72 patients with HNF1A-MODY, 72 with GCK-MODY, 53 with type 1 diabetes (T1DM), 70 with type 2 diabetes (T2DM), and 65 controls. Serum creatinine and cystatin C levels were measured. GFR was calculated from creatinine and cystatin C using the CKD-EPI creatinine equation (eGRF-cr) and CKD-EPI cystatin C equation (eGFR-cys), respectively. Results. Cystatin C levels were lower (p<0.001) in the control (0.70±0.13 mg/L), HNF1A (0.75±0.21), and GCK (0.72±0.16 mg/L) groups in comparison to those with either T1DM (0.87±0.15 mg/L) or T2DM (0.9±0.23 mg/L). Moreover, eGFR-cys was higher than eGRF-cr in HNF1A-MODY, GCK-MODY, and the controls (p=0.004; p=0.003; p<0.0001). This corresponded to 8.9 mL/min/1.73 m2, 9.7 mL/min/1.73 m2, and 16.9 mL/min/1.73 m2 of difference. Additionally, T1DM patients had higher eGFR-cr than eGFR-cys (11.6 mL/min/1.73 m2; p=0.0004); no difference occurred in T2DM (p=0.91). Conclusions. We confirmed that eGFR-cys values in HNF1A-MODY patients are higher compared to eGFR-cr. Some other differences were also described in diabetic groups. However, none of them appears to be clinically relevant.

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